Method for separating mixtures of liquids.



E. l. DYER & A. R. HEISE. METHOD FOR SEPARATING MIXTURES 0F LIQUIDS.APPLICATION FILED JUNE 15, I914. 1,242,784. Patented Oct. 9,1917.

2 SHEETS-SHEET l- ATTORNEYS E. I. DYER & A. R. HEISE, METHOD FORSEPARATING MIXTURES 0F LIQUIDS.

APPLICATION FILED JUNE I5. I914.

Patented Oct. 9, 1917.

2 SHEETS-SHEET 2- s m Mi M M n VE.- A m .uV: i A & 8 E w w UNITEDs'rxTEs PATENT OFFICE.

ERNEST I. DYE B, OI OAKLAND, AND ARTHUR B. HEISE, OF AVILA, CALIFORNIA.

I METHODFOB SEPARATING MIXTURES 0F LIQUIDS.

Specification of Letters Patent.

Patented Oct. 9, 1917.

Application filed June 15, 1914. Serial No. 845,060.

To all whom it may concern:

Be it known that we, ERNEST I. DYER and States, residing the said DYERat Oakland,

in the countyof Alameda and State of California, and the said Hnrsn atAvila, county of San Luis Obispo, California, have invented certain newand useful Improve- ,ments in Methods for Separating Mixtures ofLiquids, of which the following is a specification.

This invention relates to the art of separating mechanical mixtures ofliquids such as emulsions of oil and water, and particularly to thosepeculiarly stable and refractory emulsions which occur in connectionwith the asphaltic petroleums of California. While the processhereinafter described is applicable to the treatment of hydrocarbon oilsin general, it is'more especially designed for the treatment ofpetroleum emulsions of the type mentioned, and in the followingdescription of our process, for the sake of clearness, its adaptation tosuch oils will be economically separated from the oil by settling,moderate heating, blowing with air or by the application of the otherwell known means usuallv resorted to for such purposes. Several methodshave been developed which are suitable for use under proper conditions,but as far as we know, none as yet has been developed which possessessuch characteristics as render it suitable for use under a great varietyof adverse circumstances.

It has been recognized for some time, in connection with the oilindustry, that it would be highly desirable to develop a simple,economical and safe method for breaking down these refractory emulsionsby mechanical means alone. It is well known that the water is containedin the oil in the form of small globules, -many of which are so small asto be invisible except under the microscope. These globules behave as ifthey were inclosed by an exceedingly tough protecting skin, whichresists rupture with great tenacity. In some cases their form may beaccounted for by well known capillary-eflects due to the surface tensionexist liquids; in others, ARTHUR R. HEIsE, citizens of the Umted I tendto show that the globules of water are actually surrounded by atenacious envelop ing between the interfaces of non-miscible laboratory,experiments composed largely of substances of greater speclfic gravitythan the mean specific grav- 1ty of the oil itself. It may be com osedof heavy asphaltic substances derived 0m the 011, such as J0 calledasphaltenes or of any other substances present in the oil whether or notof origin foreign to that of the oil itself. Whatever the composition ofthis envelop may be or whether it ma be only a capillary film of thewater or o the oil or both, we have discovered that the water can not becompletely separated from the oil without destruction of this envelop orinterfacial capillary film or films. Centrifugal devices have succeededto a certain extent in eliminating some of the water, but their lack ofeffectiveness has been such that their application has never beenextensive. Electrical methods have been developed which depended fortheir action on imparting electrical charges to the suspended particles,causing them to coalesce, but these methods have not as yet found greatfavor in the oil fields.

The present method for the successful treatment of the petroleumemulsion for breaking down the envelop, whether it be an actual physicalmembrane made up of substances of composition different from the oilitself or derived from the oil, or merely a film either of oil or ofwater, is to sub ect the flowing body of oil undertreatment to suchpressures as to force the oil through a multiplicity of minute orcapillary passages of such dimension that distortion of the form of theglobul with subsequent rupture of its skin necessa ily results. Thischange of form tends to d stroy the equilibrium in the case of capillarfilms due to surface tension and in the c e of actual physical envelopsas above d scribed, to set up both tangential and ra ial stresses suchthat in either case rupture ill ensue; and inasmuch as such rupture illthen take place in a space of capillary dimensions all such rupturingglobules wi 1 be within such a short distance of each 0 her as to enablethe cohesive or capillary forces to cause their contents to agglomera eor coalesce.

We take advantaige of the known fact that of all forms which matterassumes, the

sphere has the largest volume for the least extent of surface and thisis the form assumed by particles of one liquid suspended freely inanother when in a state of equilibrium. In order, therefore, to destroythe equilibrium of the envelop, it becomes necessary to change the formof the globule, for by, so changing the form the extent of surfacenecessary to inclose a given mass is increased and stresses are set upin the envelop or capillary film tending to destroy the equilibrium, andif a time limit is introduced such that the change of form takes placeduring a period so short as to make it irpossible for the film tostretch or readjust itself to the new form by migrations of particlesfrom other portions of the film, the film will break and as thedisruption occurs in the presence of and within capillary reach of otherand similar particles, coalescence of their contents will result.

In the case of dense emulsions where the particles, originallyisphericalin form, are in contact, the figure assumed by them is polyhedral in astate of equilibrium. These polyhedra being forced into a capillarypassage are subjected to unsymmetrical forces through friction, impact,capillary action or other causes with, attendant destruction of theirenvelops, the result being the same as in the case of the freelysuspended spheres and for the same causes.

Oil and water flow through small openings with difierent degrees offreedom, whether the effect be caused by capillary action, frictionalresistance, the viscosity of the liquid itself or other causes. As aconsequence, in forcing a mixture of oil and water through a very. smallopening, the tendency is for the two components of the mixture to moveat different velocities, so that certain portions of the stream maybecome relatively rich in water and others rich in oil. This tendencyfacilitates the separation of the two liquids after rupture of theenvelops in the case of emulsions and at the same time tends to preventtheir reemulsification.

By practical experiments, as we have proven, emulsions of water and oilcan be permanently broken down in the manner described and the watercontained in the disrupted globules completely separated from the oil.

The flowing body of emulsion to be treated is forced through amultiplicity of capillary passages of a capillary medium,

which medium may be provided in a great many ways. For example, we mayuse a closely woven cloth, any material of a porous character, a mass offinely divided mineral matter such as infusorial earth; in fact, anybody or combination of bodies through which pass openings of capillarycharacter. The emulsion may be caused to pass through the capillary bodyeither by means of a pump, elevated tank or other suitablepressure-developing device on the inlet side or by a vacuum pump, siphonor-other suitable device for deriving pressures lower than atmosphericon the outlet side. Under certain conditionsthere may be employed anycombination of any of the abovemeans for creating a difference inpressure between inlet and outlet sides of the capillary substance.

We have found in carrying out our method that inasmuch as surfacetension is decreased by elevation of temperature, the emulsion may bebroken down with greater ease by a heating of the same prior to aforcing thereof under pressure through the capillary medium for breakingdown the globules to free or liberate the water therein, and furtherthat through the same cause the tendency for reemulsification of thetreated emulsion is minimized, inasmuch as the ability of the water toform an emulsion with the oil is diminished due to the lessened surfacetension caused by the increase of temperature. Therefore, while we givepreference to the raising of the temperature -.of the emulsion fortreatment prior to forcing the same under pressure through the capillarymedium, we do not wish to be understood as so restricting the invention,

Any suitable form of an apparatus may be employed for carrying out theinvention, the one illustrated in the accompanying drawings disclosing asimple and efiicient apparatus for this purpose, and wherein Figure 1 isa diagrammatic view in elevation of an apparatus for heating theemulsion for treatment and forcing the same through a connected systemof capillary mediums for breaking down or destroying the globules forliberation of the water contained therein.

Fig. 2 is an enlarged detail sectional view disclosing a system ofconnected capillary mediums.

Fig. 3 is a sectional plan view taken on line a:mFi-g. 2 of thedrawings.

In the drawings, the numeral 1 is used to designate any suitablyconstructed or receiving reservoir for the emulsified oil to be treated,which tank may be elevated at a height above the capillary medium,sufficient to give the desired pressure for forcing the emulsion of oilthrough the said capillary medium, but preference is given to theemployment of a pump 2. Tank 1 is shown equipped with a steam coil 3,which may be used to decrease the viscosity of the oil and cause acertain amount of the free water contained in the emulsion toprecipitate out under favorable conditions, and at the same time enablethe oil to flow through the inter-connecting piping 3 with greaterfacility. The emulsion flowing through the nectmg ipe 4. This heater maybe used indepen ently of coil 3 or in conjunction with it, and ma bealso furnished with live steam or any at er suitable heatin medium. Fromthe pump 2 the emulsifiedo is forced through a connection 5 to anysuitably constructed form of a capillary separator 5'. In thisillustration of the separator is disclosed a diagrammatic representationof an apparatus resembling a filter press of conventional form andconstruction. As this form of apparatus is well understood a detaileddescription will not be necessary. In general it Wlll be seen to consistof a series of frames 6, clamped together by means of a screw 7, in sucha, way that the emulsified oil flowing from the connection 5 is causedto enter by opening 8, following the course indicated by the arrows.During its passage through the apparatus it, is forced under ressurethrough the interstices of the cap- 1llary mediums, each consisting of alayer cake 9 of mineral materialfsuch as infusorial earth on the outersurface of a cloth 9', which is backed by a screen or perforated plate10, which plate serves to reinforce the. cloth and revent its tearingand at the same time a ords a relatively free opening through it. Afterpassing through t e capillary medium or mediums, the oil with its waterparticles or contents freed or 'liberated from its inclosing envelop,passes out throu h the openings 11, into the trough 12, and t rough theplpe 13, to a suitable place of deposit, such as the tank 14. This tank14 is equipped with suitable outlets so that the water whichprecipitates out almost immediately may be drained ofl independently ofthe oil from time to time, through the outlet pipe 15, connected withthe bottom of the tank, while the oil rising within the tank 14: escapestherefrom through the overflow outlet pipe 16, connected near the top ofthesaid tank, as shown. With this arrangement thedried oil will flowcontinuously out of the discharge outlet 16, to a suitable place ofdeposit and the water dibcharge through the pipe 15. The capacity of thecapillary separator may be increased to any desired extent by eitherincreasing the surface area of the filtering mediums, or increasing theconnected number thereof.

By an extended series of experiments with thev most refractory emulsionswith which we have had experience, taken from the Santa Maria oilfieldsin California, we have V been able to effect almost. completesepara- I tion of the water content with an apparatus of the typeillustrated. On applying totlie receiving or outer surface of the cloth9' a layer or cake of diatomaceous earth in a finely divided state, wehave found-v that under some conditions the effectiveness of theoperation is increased, so that by careful tests we have been able toremove substantially all of the emulsified water content in the mannerdescribed.

The method herein described for separating mixtures of*liquid mustmot betreated as a process filtering operation, for such is not t e case. Infiltration, the object is to remove a solid or more or less solidsubstance from a liquid, and the substances are separated by theintervention of a porous substance which is impervious to one of them sothat during the filtering operation one substance passes on, leavin theother behind and deposited on the tering medium. Under the presentinvention, the primary object is to separate two liquids, especially anoil and water emulsion. Both of these substances pass together throughthe porous or capillary medium, which in this case acts not as a filteror strainer, but as a device for breaking down or destroying theglobular particles of the emulsion as described, in order to free orliberate the water confined therein, no separation of the liberatedwater from the oil taking place until the capillary or porous medium hasbeen entirely and practically simultaneously traversed by both liquidsand the two brought to a state of rest or of motion at relatively lowvelocity out of contact with the porous or capillar medium. ln the caseof such oils as may be wet or emulsified, due to the presence of minutesolids or mineralmatter or other foreign substances in a finely dividedstate, forming a nucleus about which water tends to gather or beabsorbed, the operation may be facilitated by retaining such substanceson the capillary medium, these substances tending to take the place ofthe diatomaceous earth described above. In this case the mineral mattermay act as a positive aid to separation, and with such oils the removalof these foreign substances is purely incidental to the primary functionof the process, so that such filtering action as may occur is ofsecondary consideration, although the removal of these particles, in sofar as the presence of water may depend upon them, will tend to preventremulsification.

Owing to the extreme simplicity of the apparatus necessary to apply ourprocess and the moderate pressures which we have found are required toforce the oil through the capillary openings of the mediums thereof, thecost of construction thereof and of the treatment of the emulsified oilis low, and, as a consequence, the described process will appeal to andprove extremely valuable to the small producers of oil who cannot sellready and inexpensive means'of overcoming.

the difliculties which have heretofore existed. On board ship, in powerplants and in connection with other industrial operations using oil fuelwhere for some causeor other a supply of wet oil may have been receivedthrough inadvertence, this process enables the water to'be removedcontinuously during ordinary every-day operation. The water removedcarries with it such salts as may be in solution, rendering the oilsuitable for use in refineries without destructive efl'ects on stillsandother apparatus. At the same time it eliminates trouble in furnacesand oil burners due to clogging through precipitation of salts and insuch industrial processes as require heat to be derived from ahydrocarbon uncontaminated with such salts, it provides suitable relief.In the removal of water from valuable refining oils the process may beconducted in a closed cycle thereby preventing losses by evapora: tionwhich are now incidental to all other methods with which we are as yetfamiliar. As the operation is conducted under relatively low pressureand at temperatures but slightly exceeding the normal and without theapplication of electricity at high potential, all danger to life andproperty is obviated.

Having thus described the invention what we claim as new and desire tosecure protection by Letters Patent is 1. The method of separating waterfrom emulsified mineral oils, which consists in breaking down the shellof the water envel, oping globules to liberate the confined water byforcibly ejecting the body of oil through a capillary medium.

2. The method of separating particles of water from emulsified mineraloils which consists in simultaneously passing both com ponents through acapillary medium under pressure to break down the inclosing filmof theglobules of one liquid to free the other liquid therefrom.

3. The method of separating water from emulsified mineral -oils whichconsist in liberating the. water by breaking down or puncturing underpressure the inclosing shell of the globules within which the water isconfined.

4. The method of freeing and separatin water from emulsified mineraloils, whic consists in breaking or puncturing the covering film of thewater confining globules V by forclbly passing a body of flowing emulsified mineral oil through a capillary medium, and thence overflowing theoil from the water. 1 5. The method of freeing and separating water fromemulsified mineral oils, which consists in first raising the temperatureof the body of oil to be treated, and thence breaking down the film ofthe water confining globules by forcibly ejecting the said oil through acapillary medium.

6. The method of separating Water from emulsified mineral oils, whichconsists in liberating the water by forcibly ejecting the oil through acapillary medium to break down the water confining globules, thenceconveying the water and oil to a place of deposit, thence withdrawingthe oil and water cibly passing the same through a capillary member,causing the released internal phase of the'mixture tocoalesce, leadingthe separated liquids to. a place of deposit, and withdrawing one fromthe other.

9. The method of freeing and collecting particles of one liquidsuspended in another, which consists in forcibly ejecting the mixturethrough a capillary medium to break down the inclosing film for theinternal phase of the mixture, causing the internal and external phasesof the mixture to coalesce separately beyond the capillary mediumthrough which the mixture is forced, and thence leading the separatedliquids to a place of deposit.

10. In the herein described method of treating oily materials containingmineral oil and impurities insoluble therein, the ste which comprisespassing said oily materials first through small perforations in a memberand thereafter through perforations in a separate member, said twomembers being spaced from each other, and then allowing said oilymaterials to separate by difierences in the specific gravities of saidmineral oil fraction and the fraction constituting said impurities.

11. A method of treating oily materials containing emulsified impuritiesnot readily separable by gravity, which comprises passing said oilymaterials successively through a plurality of foraminous members, spacednames to this specification in the presence from feachdotheri) theEGIfOIfitlOfIS in at least of two subscribing witnesses. one o "sai memers aving at east one extremely small dimension, and thereafter al- 5lowing said oily materials to separate by difl'erences in the specificgravities of its Witnesses: constituents, N. A. AOKER,

In testimony whereof we have signed our D. B. RICHARDS.

